How Brewers are Using Coolships to Create Wild Fermentations

By Joshua M. Bernstein

Photo by Marcus Nilsson

During the frosty depths of winter, Daniel Acosta keeps close tabs on the thermometer. The founder and head brewer of LIC Beer Project in Queens, New York, Acosta is hoping for a night that’s about 30˚F, and one that doesn’t fluctuate more than 10 degrees in either direction.

“The minute the weather is right, we’re ready to get the wort in there,” says Acosta, referring to the soupy grain mixture that becomes beer. “There” is the coolship, a shallow vessel that looks like an oversized baking pan. In it, the wort gets exposed to air, and its teeming microbes and bacteria can settle into the liquid and begin to snack, which creates a beer with a distinct DNA.

Most commercial beers are brewed with cultivated yeast strains favored for dependable flavors and aromas, and consistent beers created in as little as a couple of weeks. In a world where every brewery has access to the same hops, grains and store-bought yeast strains, spontaneous fermentations help brewers stand apart. Increasingly, American brewers are installing coolships and flinging the windows wide open to let nature take its course.

Recommended beers

De Garde Brewing | The Kriek

The coastal Oregon operation focuses exclusively on spontaneous fermentation, and will barrel-age its beers for years before they’re deemed ready to drink. This red ale finds its acidity complemented by sweet and tart cherries.

Allagash Brewing Company | Belfius

To extend its stock of spontaneous fermentations, Allagash blends a portion with a peppery saison to create a balanced sour that’ll appeal to people averse to unbridled acidity.

Oxbow Beer | Native/Wild

The rural Maine brewery uses local grains and well water in tandem with indigenous yeast to craft this lemony, spontaneous expression of terroir.

Black Project Spontaneous & Wild Ales | Dreamland

The tingly golden sour, made from a mixture of beers more than two years old, flaunts a delicate, fruity profile evocative of apricot and peach.

Jester King Brewery | SPON—Three Year Blend

Méthode Traditionelle is the term that the Texas Hill Country brewery uses to describe its natural inoculations like the aptly named SPON, a blend of vintages from one to three years old.